Patent US5138479A successfully refreshed from Google Patents.
US5138479A
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US
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Light beam scanning apparatus and method of detecting a variation of a scanning speed of a light beam
Assignee: Canon Inc
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Filing: 1990-09-25
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Granted: 1992-08-11
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Expires: 2010-09-25
Abstract
Abstract A light beam scanning apparatus has a light source, a deflecting element for deflecting a light beam from the light source, such as a rotary polygon mirror, a drive component for driving the light source, a measuring means for detecting the light beam deflected by the deflection element and measuring the scanning speed of the light beam, and a control system for controlling the drive component in accordance with signals from the measuring device. According to this composition, even if the scanning speed is cyclically changed in each scanning, it is possible to restrain an image on a medium to be scanned from being deteriorated by the change.
Inventors
- 👤 Toshinori Ando
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:37
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/0025; G02B27/0031; H; H04; H04N; H04N1/00; H04N1/04; H04N1/047; H04N1/053; H04N1/113; H04N1/1135; H04N1/12; H04N2201/00; H04N2201/024; H04N2201/02406; H04N2201/02439; H04N2201/04; H04N2201/047; H04N2201/04701; H04N2201/0471; H04N2201/04712; H04N2201/04732; H04N2201/04739; H04N2201/04744; H04N2201/04753; H04N2201/04758; H04N2201/04767; H04N2201/04793; H04N2201/04794
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
113 words
A light beam scanning apparatus, comprising: a light source; deflecting means for scanningly deflecting a light beam from said light source; drive means for driving said light source; measuring means for detecting the light beam deflected by said deflecting means and measuring the scanning speed of the light beam, said measuring means having a first light sensing unit provided at a scanning start side for detecting a scanning start signal, and a second light sensing unit provided at a scanning end side, said second light sensing unit including a plurality of photoelectric conversion elements arranged in a scanning direction; and control means for controlling said drive means in accordance with said measuring means.
Claim 2
Dependent Claim
113 words
A light beam scanning apparatus, comprising: a light source; deflecting means for scanningly deflecting a light beam from said light source; drive means for driving said light source; measuring means for detecting the light beam deflected by said deflecting means and measuring the scanning speed of the light beam, said measuring means having a first light sensing unit provided at a scanning start side for detecting a scanning start signal, and a second light sensing unit provided at a scanning end side, said second light sensing unit including a plurality of photoelectric conversion elements arranged in a scanning direction; and control means for controlling said drive means in accordance with said measuring means.
Claim 3
Dependent Claim
20 words
A light beam scanning apparatus according to claim 1, wherein said deflecting means has a plurality of deflecting reflection planes.
Claim 4
Dependent Claim
37 words
A light beam scanning apparatus according to claim 2, wherein said measuring means measures a cyclic change in the scanning speed of the light beam deflected by each of said deflecting reflection planes of said deflecting means.
Claim 5
Dependent Claim
27 words
A light beam scanning apparatus according to claim 1, wherein said control means changes an image signal transmitting clock in accordance with signals from said measuring means.
Claim 6
Dependent Claim
24 words
A light beam scanning apparatus according to claim 1, wherein said drive means drives said light source in accordance with the scanning start signal.
Claim 7
Dependent Claim
42 words
A light beam scanning apparatus according to claim 1, wherein a pulse light emission arises on said second light sensing unit when a predetermined time has passed after the light beam deflected by said deflecting means passes said first light sensing unit.
Claim 8
Dependent Claim
121 words
A light beam scanning apparatus, comprising: a light source; a photoconductive member; deflecting means for scanningly deflecting a light beam from said light source to scan said photoconductive member; drive means for driving said light source; measuring means for detecting the light beam deflected by said deflecting means and measuring the scanning speed of the light beam, said measuring means having a first light sensing unit provided at a scanning start side for detecting a scanning start signal, and a second light sensing unit provided at a scanning end side, said second light sensing unit including a plurality of photoelectric conversion elements arranged in a scanning direction; and control means for controlling said drive means in accordance with said measuring means.
Claim 9
Dependent Claim
121 words
A light beam scanning apparatus, comprising: a light source; a photoconductive member; deflecting means for scanningly deflecting a light beam from said light source to scan said photoconductive member; drive means for driving said light source; measuring means for detecting the light beam deflected by said deflecting means and measuring the scanning speed of the light beam, said measuring means having a first light sensing unit provided at a scanning start side for detecting a scanning start signal, and a second light sensing unit provided at a scanning end side, said second light sensing unit including a plurality of photoelectric conversion elements arranged in a scanning direction; and control means for controlling said drive means in accordance with said measuring means.
Claim 10
Dependent Claim
24 words
A light beam scanning apparatus according to claim 7, wherein said drive means drives said light source in accordance with the scanning start signal.
Claim 11
Dependent Claim
42 words
A light beam scanning apparatus according to claim 7, wherein a pulse light emission arises on said second light sensing unit when a predetermined time has passed after the light beam deflected by said deflecting means passes said first light sensing unit.
Claim 12
Independent Claim
137 words
A method of detecting a variation of a scanning speed of a light beam in a light beam scanning apparatus, said method comprising the steps of: disposing a first light sensing unit on a scanning start side of the light beam for detecting a scanning start signal and a second light sensing unit in which a plurality of photoelectric conversion elements are arranged in a scanning direction of the light beam on a scanning end side of the light beam; scanning the light beam and causing a pulse light emission to arise on said second light sensing unit when a predetermined time has passed after the scanned light beam has passed said first light sensing unit; and detecting a variation of a scanning speed of the light beam from an output of said second light sensing unit.
Claim 13
Independent Claim
137 words
A method of detecting a variation of a scanning speed of a light beam in a light beam scanning apparatus, said method comprising the steps of: disposing a first light sensing unit on a scanning start side of the light beam for detecting a scanning start signal and a second light sensing unit in which a plurality of photoelectric conversion elements are arranged in a scanning direction of the light beam on a scanning end side of the light beam; scanning the light beam and causing a pulse light emission to arise on said second light sensing unit when a predetermined time has passed after the scanned light beam has passed said first light sensing unit; and detecting a variation of a scanning speed of the light beam from an output of said second light sensing unit.
Claim 14
Independent Claim
59 words
A method of detecting a variation of a scanning speed of a light beam in a light beam scanning apparatus, said method comprising the steps of: scanning the light beam; measuring a distance where the scanned light beam moves in a predetermined time; and detecting a variation of a scanning speed of the light beam from said measured distance.
Claim 15
Independent Claim
59 words
A method of detecting a variation of a scanning speed of a light beam in a light beam scanning apparatus, said method comprising the steps of: scanning the light beam; measuring a distance where the scanned light beam moves in a predetermined time; and detecting a variation of a scanning speed of the light beam from said measured distance.
Claim 16
Dependent Claim
45 words
A method according to claim 11, wherein said measuring step includes the step of forming an exposure distribution at the predetermined time on a light sensing unit in which a plurality of photoelectric conversion elements are arranged in a scanning direction of the light beam.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-11 | 1996-02-10 | 1996-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-11 | 2000-02-10 | 2000-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-11 | 2004-02-10 | 2004-08-11 | $7700.00 | Window Closed / Lapsed |